Thursday, February 16, 2012

Honda Civic CNG Dethroned As Greenest Car

For 8 years, the Honda Civic CNG has topped ACEEE's rankings of the greenest vehicles.  See But this year it fell to a tie for second with the Nissan Leaf in ACEEE's 14th annual rankings.  After a long reign, the Honda Civic CNG is no longer the greenest car, but it remains incredibly clean, when compared to all alternatives.  It also costs about $2 less per gallon to operate than the gasoline Honda Civic, since CNG is typically selling for between $1.25 and $2.00 per gallon.

What did ACEEE rank as the greenest car? The Mistubishi i-MIEV battery electric vehicle. The Toyota Prius, Honda Insight, and the Smart ForTwo were 4th, 5th, and 6th in the rankings.

To be ranked, a car must have more than 1,000 sales. As with all rankings, criteria and assumptions play a role.  The Chevy Volt was hurt by an assumption that it was driven 65% of miles traveled on electricity, with the remainder on gasoline.  A further assumption for electric cars was that electricity was generated by a national average mix of power plant resources.


  1. What do you mean by assumptions? Is that an assumption that the public holds about a vehicle? Our style of vehicle architecture at the Penn State Advanced Vehicle Team has been very similar to the Volt in the past (during the EcoCAR competition), and our outreach team has been working to educate the public on how these series hybrid electric vehicles work. Do you have any insight as to how communication about Volt-style vehicles could be improved?

    Let us know! My email is

    Brenna Thorpe
    Penn State Advanced Vehicle Team

  2. I am referring to the assumption about how many miles the Volt is driven on electricity versus how many on gasoline. The rankings require other assumptions like the percentage of coal, natural gas, nuclear, renewable energy that comprise grid power. And so on.